Frenning G, Strømme M
Department of Pharmaceutics, Uppsala University, P.O. Box 580, SE-751 23 Uppsala, Sweden.
Int J Pharm. 2003 Jan 2;250(1):137-45. doi: 10.1016/s0378-5173(02)00539-2.
This article presents a novel drug release model that combines drug dissolution, diffusion, and immobilization caused by adsorption of the drug to the tablet constituents. Drug dissolution is described by the well-known Noyes-Whitney equation and drug adsorption by a Langmuir-Freundlich adsorption isotherm, and these two processes are included as source and sink terms in the diffusion equation. The model is applicable to tablets that disintegrate into a number of approximately spherical fragments. In order to simplify the analysis it is assumed that liquid absorption, matrix swelling, and tablet disintegration are much faster than drug dissolution and subsequent drug release. The resulting model is shown to yield release characteristics in good agreement with those observed experimentally.
本文提出了一种新型药物释放模型，该模型结合了药物溶解、扩散以及药物吸附到片剂成分上所导致的固定化过程。药物溶解由著名的诺伊斯 - 惠特尼方程描述，药物吸附由朗缪尔 - 弗伦德利希吸附等温线描述，这两个过程作为源项和汇项包含在扩散方程中。该模型适用于崩解成多个近似球形碎片的片剂。为了简化分析，假定液体吸收、基质溶胀和片剂崩解比药物溶解及随后的药物释放快得多。结果表明，所得模型产生的释放特性与实验观察结果高度吻合。
